SU1462109A1 - Acoustic flowmeter - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the flow rate of a liquid medium transported through pipelines. The purpose of the invention is to increase the sensitivity of the flow meter and expand the flow conversion range. The device contains a pair of electroacoustic converters 2 and 3, which are excited by generator 5, a two-channel strobe circuit b, consisting of two delay lines 7 and 8, two drivers 9 and 10 strobe pulses, two switches 11, and 12 and two amplifiers 13 and 14. The device also includes a third strobe pulse shaper 15, a third delay line 16, a trigger 17, a 2I-21SH circuit, and an operational memory device (RAM) 19. 21 time intervals introduced into the device and a two-channel synchronous processor allow They precisely convert a small time difference between the time of signal propagation along the stream and against it into a large value, which can be measured with simple means with great accuracy. 4 il. o (l

Description

9d N9

1146

The invention relates to a measurement technique and can be used to measure the flow rate of a liquid medium transported through pipelines.

The purpose of the invention is to increase the sensitivity of the flow meter and expand the flow conversion range.

Fig. 1 shows a functional scheme of the proposed flow meter; Fig. 2 shows the time pulse diagram of gating of received signals downstream and against it; PA FIG; 3 - timing diagrams of sawtooth symmetrical stresses; in Fig. 4, time diagrams of a random access memory (RAM) memory cells,

The device contains electroacoust-20 inputs. Elements And schemes 2I-2ShSh 18

a cus tract 1 with reversible electroacoustic transducers 2 and 3 mounted on opposite pipeline walls, low noise suppressor 4, excitation generator 5, two-channel gating circuit 6 containing the first 7 and second 8 delay lines, the first 9 and second 10 gate drivers pulses, keys 11 and 12, receiving amplifiers 13 and 14, shaper pulse shaper 15, connected in series with the third delay line 16, trigger 17, logic circuit 2I-2ILI 18, random access memory 19, digital transducer Instantaneous consumption collector 20, time interval converter 21, dual-channel synchronous processor 22, each channel of which contains an auto-circulator 23 (24) sawtooth voltage, summing volume flow meter 25, indicator 26 instantaneous volume flow, analog converter 27 cells 28 and 29 memories these random access memory 19,

The flow meter works as follows.

From the outputs of the shaper 15, the pulses with the length At set the keys 9 and 10 of the two-channel strobe-50 circuit closed and the keys 11 and 12 of the dual channel 6, the trigger 17 in the state O, the strobing 6 into the state At the first inputs of the AND elements logical conductivity, which schemes 2I-21 of the ICU are connected with by the time d

potential outputs of delay lines 7 and 8, high levels, at the second inputs low levels, synchro processor 22 and random access memory 19 in the quiescent state.

At some instant of time tg impulse of the generator 5, through a low-level noise suppressor 4, electroacoustic transducers 2 and 3 are excited, the acoustic oscillations of which propagate opposite from one radiator to another.

Simultaneously with the moment of excitation of electroacoustic transducers 2 and 3, generator 5 generates a pulse of the onset of sending acoustic waves, which from its second output sets the unit state to trigger 17, C a single trigger output sets a high level to one of the input of delay line 16 sending acoustic oscillations through the second

five

0

five

from the output of the latter, changes the state of the delay line 16 by time.

t

about sin (C, -bV ,, cosoi)

after which this line takes the previous state, and the strobe pulse shaper produces 15 pulses of duration

ut, t; -t ;,

intended for gating signals received from the stream at the moments of the start of the flow meter and at the moments of failures in the course of its operation (see Fig. 2, graphs b, c), while

t

 З1по (-V. sinoc) diameter of the pipeline;

five

d

Where

WITH

WITH

V

respectively, the maximum and minimum speed of propagation of acoustic oscillations;

flow rate; the angle of propagation of acoustic waves relative to the axis of the pipeline.

From the outputs of the driver 15 strobe pulses of duration At, set in

"Tax

about

0, keys 11 and 12 of dual-channel gating 6 are in the conduction state,

Keys 11 and 12 of dual gating 6 are available,

After time d

55. s1p |) (, (C + Uso8og,)

since the emission of acoustic waves into the stream, where, t, the pulse received along the stream passes the public key 11 and from its output changes the state of the delay line 7 to the time

t | T-ut; ut “ut.

At the same time, this pulse changes the state of the time interval converter 21 by the time t (see Fig. 3, plot b), and the autocirculator 23 sets the voltage to the formation of the first rising front (see Fig. 3 , schedule d), and after time

, d

2 sinci (C-Vcos i)

the moment of radiation acoustic wave flow, where the impulse

in ..ch 1 vj, 4, IfJ, lg 2 - J rUIUyjlDl ,,

the open key passes the public key 12 and, from its output, changes the state of the delay line 8 for a time, and the autocirculator 24 of the saw-tooth voltage sets the state of formation of the first uplink segment (Fig. 3, graph f).

The output potentials of the delay lines 7 and 8 are for tj and tj, the elements of the AND logic circuit 2I-2ILI 18 are closed, and the autocirculators 23 and 24 of the saw-tooth voltage form the first ascending fronts. The duration of the formation is determined for 23 sawtooth voltages with a time t ° ut + t ° for the autocirculator and 24 times for a sawtooth voltage for the autocirculator with a time equal to t °. After the time t from the moment the converter starts, 21 time intervals emit a pulse which switches the autocirculators 23 and 24 of the sawtooth voltage from the state of formation of the first ascending fronts (see Fig. 3, graphs d, f) to the state of formation of the first falling fronts, sets the autocirculators 23, 24 of the fronts mirrored by the formation of the first falling fronts.

In the absence of flow, when t.

H g the duration of the upward and downward-fronted formations by the autospirator 23 sawtooth voltages is equal to the duration of the ascending and descending / fronts formation by the autocirculator 24 sawtooth voltages; In the presence of flow, when,; tj-t, ut, for n form

Yu

20

The scientific research institute of fronts is the time difference between the pulses at the output of the autocirculators 23 and 24 and is determined by the flow rate V and the number of formations.

From the output of the autocirculator 24 of the sawtooth voltage, the nth pulse of a given number of formations sets the accumulation and storage cell of the potentials of the random access memory (RAM) 19, for example, the cell 28, to the state of memorizing and accumulating potentials, and after the time At-n the pulse of the specified the number of formations switches this cell to the state of only memorizing the accumulated potential.

After the time t | from the moment of receiving the first signal in the stream, the pulse of the delay line 7 starts the driver 9, and after the time t from the moment of reception of the first signal against the stream the pulse of the delay line 25 starts the driver 10, the strobe pulses with a duration of 2or shortly set to conductivity keys are 11.12, respectively (see Fig. 2, graphs b, c).

From the output of the key 11, the signal received by the rto flow again changes the state of the delay line 7 by time t |, the state of the time converter 21 to the time t and sets the autocirculator 23 to the state of the upward and downward formations the edges in which the duration of one formation, and from the output of the key 12, the signal received against the flow again changes the state

thirty

0

five

delay line 8 at time t, sets the autocirculator 24 to state the n formations of the ascending and descending {fronts, in which the duration of the first formation is equal to t.

For p formations from the moment of receiving the signal against the flow, the autocirculator 24 outputs a pulse, which again sets, for the time η-Qt, the cell 28 of the random access memory 19 to the potential accumulation state, after which the pulse of the autocirculator 23 transfers this cell to the state remembering g on accumulated potential.

Cells 28 and 29 work alternately, and the potentials accumulated by them are limited to a given level V, the achievement of which is indicated by a pulse of weight Q taken per unit volume flow. In addition, this pulse switches the working cell to the state of discharge of the accumulated potential (see diagram b), and the initial cell to the state of accumulation of the Potential.

-Pulses weighing Q from the output of RAM 19 Enter the summing counter 25, which highlights the total volume flow in increasing order and the number of pulses weighing Q in one second; the second displays the instantaneous volume- ijibM flow and flashes the instant volume flow indicator. To connect to the ACS, the flow meter has a 4-logic output of discrete signals - jjiOB and an output of analog unified signals.

Invention Formula I Acoustic flowmeter containing two reversible electroacoustic 25 tel and dual channel synchro processor, 1 rebracer, installed on each channel of which contains auto-opposite pipeline walls, excitation generator, shaper of ftrob pulses, noise suppressor,; which contains a post-i; i-connected delay line; a strobe pulse shaper, a key and an amplifier connected by the first key inputs to the shaper outputs a coffin pulse sequentially connected to the third linfi of the delay, and the outputs of the keys are connected to the inputs of the delay lines of the corresponding channels, a trigger connected to the second output of the exciting generator, and the 2I-2IL circuit, the first and second element inputs

five

0

which is connected respectively to the potential outputs of the delayed gating circuit delayed circuit, the third input is connected to the trigger input, and the output is connected to the first input of the third delay line, the second input of which is connected to the trigger output, a random access memory connected to the digital converter; the first and second reversible electroacoustic transducers are connected to the outputs of the amplifiers of the two-channel gating circuit and through the low-level noise suppressor - I excite the first output its generator, characterized feM, that, in order .povysheni flowmeter sensitivity and expansion of functionality incorporated therein converter timeslots totaliser volume flow indicator instantaneous volume flow, analog preobrazova0

five

0

the sawtooth voltage circulator, the first inputs of sawtooth voltage autocircuits are connected to the outputs of the corresponding dual-channel strobe key, their second inputs are connected to the output of the time interval converter, and the outputs are connected to the inputs of the operational storage device, the second, third and quarter of which are connected to the inputs of a summing volume flow meter, instantaneous volume flow indicator and analog converter, while the input of the converter time slots connected to the output of the key and the input of the first delay line.

FIG. 2

Fi.Z

FIG.

Claims (2)

Claim Acoustic flowmeter, two reversible electro-acoustic contents 2 Converters installed on the Opposite walls of the pipeline, an exciting generator, a pulser fotrob pulses, a noise suppressor, a two-channel gating circuit, each channel of which contains a delay line connected in series; ki, strobe driver, key and amplifier, connected by the first key inputs to the outputs of the strobe driver, sequentially j connected to the third delay line, and the key outputs connected to the inputs of the delay lines of the corresponding channels, the trigger connected to the input of the second output exciting generator, and the circuit 2I-2OR, the first and second inputs of the elements of which are connected respectively to the potential outputs of the delay lines of the two-channel gating circuit, the third input to the input of the trigger, and the output to the first at the input of the third delay line, the second input of which is connected to the trigger output, a random access memory connected with the j output to the digital transducer, while the first and second reversible electroacoustic transducers are connected to the outputs of the amplifiers of the two-channel gating circuit and πες cuts a low-level noise suppressor with the first output excitation generator, characterized in that in order to increase the sensitivity of the flowmeter and expand the functional capabilities, a converter is introduced into it time intervals, a totalizing volumetric flow meter, an instantaneous volumetric flow indicator, an analog converter and a two-channel synchro-processor, each channel of which contains a sawtooth autocirculator, the first inputs of the sawtooth autocirculators connected to the outputs of the corresponding key of the two-channel gating circuit, their second inputs connected to the output of the temporary converter interval, and the outputs to the inputs of random access memory, the second, third and fourth the outputs of which are respectively connected to the inputs of the summing volumetric flow meter indicator obemYaogo instantaneous flow rate and the analog converter, the converter input time slots connected to the output and a key input of the first delay line.